MySQL中删除重复数据只保留一条

使用SQL删除表中重复数据（单字段）：

1.查询重复数据：

SELECT
*
FROM
info_1688
WHERE
storeURL IN (
SELECT
storeURL
FROM
info_1688
GROUP BY
storeURL
HAVING
COUNT(storeURL) > 1
)

2.删除重复数据：

DELETE
FROM
info_1688
WHERE
storeURL IN (

SELECT
storeURL
FROM
info_1688
GROUP BY
storeURL
HAVING
COUNT(id) > 1

)
AND id NOT IN (

SELECT
MIN(id) AS id
FROM
info_1688
GROUP BY
storeURL
HAVING
COUNT(id) > 1

)

Mysql异常：you can’t specify target table ‘info_1688’ for update in FROM clause

解决方法：select的结果再通过一个中间表select，可以避免此错误

DELETE
FROM
info_1688
WHERE
storeURL IN (
SELECT storeURL FROM (
SELECT
storeURL
FROM
info_1688
GROUP BY
storeURL
HAVING
COUNT(id) > 1
) AS tab1
)
AND id NOT IN (
SELECT id FROM (
SELECT
MIN(id) AS id
FROM
info_1688
GROUP BY
storeURL
HAVING
COUNT(id) > 1
) AS tab2
)